v0.9

First substantive release since the 0.8 prerelease import from U-Boot.
This release captures the spec's evolution into a more thorough,
self-contained document.

Highlights

Security

• New chapter documenting the security architecture and hash contents
• Worked example of configuration signing showing exactly which bytes are hashed
• Clarified that hashed-nodes is a signer hint, not a guarantee

Filesystem images

• dm-verity support for filesystem-type images, allowing the bootloader
  to construct kernel command-line parameters for integrity-verified boot

New image and configuration features

• tfa-bl31 image type for ARM Trusted Firmware-A BL31
• cmdline property in configuration nodes
• Multi-step loading support
• ramdisk property documentation completed

Structure and editorial

• Security content moved to its own chapter
• Chapter files renamed to match output numbering
• Titles added to all documents
• start-address reworded as load address for clarity
• /images optional subnodes promoted to their own subsection
• Various typo fixes and admonition style cleanups
• Patch-submission docs corrected

Notes

• Internal version macros at this point still read 0.8; the v0.9 tag is
  the official release marker. The next release (1.0) will update these.